> For the complete documentation index, see [llms.txt](https://docs.openbrim.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.openbrim.org/examples/concrete-bridge-examples/example-prestressed-i-girder-concrete-bridge-ex1-pig/bridge-geometry-ex1-pig/insertion-point-ex1-pig.md).
# Insertion Point
This section defines the insertion points for girder placement. Each bearing requires at least one insertion point, and precast girders need insertion points at both their start and end locations.
{% hint style="info" %}
**Navigation:** Bridge Geometry > Insertion Point
For detailed parameter explanations, see the [Insertion Point Reference](https://docs.openbrim.org/templates/precast-i-girder-bridge-workflow/bridge-geometry-pig/insertion-point-pig).
{% endhint %}
## Steps
### Step 1: Navigate to Insertion Point
Navigate to **Bridge Geometry > Insertion Point** in the tree view.
### Step 2: Create First Insertion Point
Click the **three-dots icon** on the first cell under **Location** and set it to **Abut1**.
### Step 3: Define Insertion Points at Abut1
Since there are five girders from Abut1 to Pier1, define five insertion points at Abut1. Enter the **Transverse Offset** and **Longitudinal Offset** values for each insertion point as shown.
### Step 4: Create Remaining Insertion Points
Repeat the process to create insertion points at all support locations (Pier1, Pier2, and Abut2), setting the appropriate transverse offset values for each.
Quick Tip: Skew Angle and Offset Calculations
For support lines with skew angles greater than 0, special calculations are needed:
**Transverse Offset (T value):** User must enter the T value for skewed supports.
**Longitudinal Offset:** For skewed support lines, the longitudinal offset must account for the skew angle.
Quick Tip: Transverse Offset Direction
Offset values use the Profile Grade Line (PGL) as the reference point.
## Verification
{% hint style="success" %}
After completing these steps, your insertion point layout should match the view shown below.
{% endhint %}
### Video Walkthrough
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.
Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:
```
GET https://docs.openbrim.org/examples/concrete-bridge-examples/example-prestressed-i-girder-concrete-bridge-ex1-pig/bridge-geometry-ex1-pig/insertion-point-ex1-pig.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.